\documentclass[11pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[french]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{fancybox}
\usepackage{algorithm,algorithmic}
\usepackage{array}

%Tree drawing
\usepackage{tikz}

%Link in PDF
\usepackage{hyperref}